APOE and Alzheimer disease: In our Korean population data set, the APOE ɛ4 status showed the highest effect size among the factors, including the PRS, confirming that the APOE ɛ4 status is an important risk factor for AD dementia across various ancestries.25 However, risk stratification based on the APOE ɛ4 status alone might be insufficient because individuals are classified into only 3 genotypes (APOE ɛ4 noncarrier, heterozygous carrier, and homozygous carrier), and this status does not provide sufficient explanation of the phenotypic variance of AD.